The News-Herald. [volume] (Hillsboro, Highland Co., Ohio) 1886-1973, 1887-08-25

w inu VUOye uACV AoWes WuiCh oiC AOWS
by the aid Of the barometer, pretty
well understood. We are all famil-
lar with the dust.whirls that fire.
quently start up in our streets and speed
lily expend their little energy. They are
the result of the encounter of two small
opposing currents of air. From the
small we learn of the great. Now, let
US look for moment at the cause Of our
frequently tumultuous sea Of air, the
hills and the hollows, upon which
weather prediction is founded.
Unlike the majestic circuit over the
inter-tropical regions, called the trade
and the anti-trade winds, the opposite
currents over the middle latitudes, COM
monty known as the equatorial and the
polar currents, skim along nearer the
earth, frequently intermingle and by
duce atmospheric disturbances, some
times purely local, as the tornado and
thunderstorm, and sometimes covering
vast areas of the earth's surface, as in
cyclones. In our latitudes the general
surface or equatorial current coming
from the Gulf of Mexico and the South
ern seas is warm and humid; the upper
return or polar current coming from the
polar regions is cold and dry. These
two opposite currents of the middle lati-
tudes are the theatre of our weather-its
changes and phenomena.
Solar heat is the prime disturbing force,
and the air which is heated mainly at the
bottom of the atmospheric ocean ex-
pands, becomes lig ter and ascends. This
isillustrated by the draught when we build
fire in our CRATES. The heat of the fire
creates an upward current of air which,
were 1t not for the general law control
ling the motion of all liquids, would leave
vacuum. The rarefaction and upris-
ing of large body of air diminishes its
weight or pressure upon the earth which
the barometer reveals. As the pressure
upon the mercury in the cistern of the
barometer is lessened, the column of mer-
curry in the tube sinks, and we call this
falling barometer. On the other hand, as
pressure upon the mercury in the cistern
increases, the column in the tube rises,
and this Is rising barometer. 1t may be
we'll to state that normal weight or press
ire of the atmosphere is when column
If air having the same base as the col
INN Of mercury in the barometer sus-
tains the latter at the height of thirty
inches. When by reason of diminished
weight of air the column of mercury sinks
considerably below that, it is called
low, and when, by reason of increased
weight of air, it rises in the tube consid-
-rably above that, it is called q high
barometer.
Now, when heated, vaporized air Of
the lower strata of the atmosphere rises
and enters the upper strata, where the
cold return or polar current flows along
in an opposite direction, a whirl or gyra-
tion is initiated. This results in a circu-
lar movement, having for its centre the
:.rea wnere .ne pressure ID nast. ine
.hI.iai gylatlon pells eStapiisheu, GA
,enus uowhwaru anu IN az ulrections
h ana moves forward upon !ne surface OF
.nT sal'n as On nrea ma Vi cilons wnus'
oa.,eu U. cyelone. ane PlosressiSe sI move, .t
inent VI .ne cyclone is .iaceu On .ne
mea'hel maps il1m uay W uat i.s Ioh.
;oui consIantly cnahg.ng.e me cycione
is senerat movement oi q portion ol
1ne aa;:nospnere .oWaru u Seht5at area
~ tnis h. nosenlsh. 80; ;ne VIM Is % uenec.eu
W VIZ :S' niSS' anu sniS .i Iie".es aenu.noy
W i1,. orouia.e aaounu :ne oen'ie I:.; Mh.n
'plraly inward motlon. In adaitlon
70 tne upwaro movement, ,ne centIllugal
,o.e iesuitng s;ii taoM circuia.,on apout
oen..o .os s ~ ,h .aanhono ~; ;.H;,
VI pieSsuae VI Ti' IMG a.mospleIe Mi.nin 'ne 9
een.lai e. area !is upMalu iao' o'eMen' VI
.ie mat ~ aid nau ~. ALLY. OIL i..o .ne upper re,
s,ohs on ; coiu "a ar Ire tesua;s IN elouGs ana
inaiiy ia:1, anu 'no iain aiea, - 10 VI
any th mas an o1In,
up9n .no ~ i S:; VI Hoiow w
mhiohp " IpG os ne seicSy Ny anu tha aestUn ~
W. tha atno.nhoro I wv for nr;i;hris 40 @ su,sEie be
heated mnist and ,;sht HHnria;nr a;r 'is is
% renlaced % hu Snwn&nenr @ & of the ne,d o. drn ~
and boav1 o;- ~ tbe ,,nnor w." ran;or, ~ ~
the atmosgbere Th;s deIpcppnd;ng ppd e c,,rrout urr ~
str;res the surface beaninr IN and on'
cumnIat;no mnt;I tbare 10 ybat bp IL teob-
n;caiiw caI1sd an "areo nf hirh haronna-
tarn ~ antiec~clora This dewrmnvr nf
the cold drv .;r nf tho mrnor rer;nns W
started M hv tie m mnrisinr of b tbe warm iiah,
surface 9ir maI narbons ' somewhat ;n'
eleean,,v ba comnared 70 q stream ", ' nf
sand falling from some elevation mon
the the surfaces ''H II unon an ,"en mneven upUn s"r.
face We nomr a stream ~ sanI T. vii,
sorm a dama.,;Le hi down tha s;das -,
.lonas ~ wh;nh the ssnI nor,;oias vii III
% low with vi % q va,ocitv & sa~ accorSina ,.s to % tha
rboroctor ~ tho sHrromnd;nr srrfooa
~ tuCIO Uo D uOllOW ~ tuc Udsc VI tuls